Closure means for cylinder units



June 16, 1959 R. PRINCE 2,890,917

CLOSURE MEANS FOR CYLINDER UNITS Filed May 20, 1957 Anvem'or Qichm'd Prince /41 25 24 r fil orw United States Patent CLOSURE MEANS FOR CYLINDER UNITS Richard Prince, Sioux City, Iowa Application May 20, 1957, Serial No. 660,351

11 Claims. (Cl. 309-2) My invention relates to a closure means for cylindrical structures and more particularly to a removable cylinder closure device.

The hollow cylinder or tubular member is utilized on many structures to perform various and important functions. Its adaptation has been particularly successful in the field of hydraulics and the hydraulic cylinder has become an item of absolute necessity on many machines. However, it is often necessary to gain access to the interiors of these cylinders, hydraulic and otherwise, and they are therefore generally equipped with at least one detachable end. These detachable cylinder ends sometimes are in the form of a cap which can be threadably placed on and removed from the cylinder. 'Other detachable cylinder ends are in the form of a casting which may extend into the cylinder and is held againstmovement by adjustable set screws which extend radially through the cylinder walls. Still other detachable cylinder closures are threadably secured to the free ends of rods which are anchored at one end of the cylinder and extend parallel thereto towards the detachable end of the cylinder. Many other more complicated cylinder closures are presently in use.

The greatest shortcoming of the above described cylinder closures is that they all require special expensive structure and/or special expensive machining to accomplish their detachable characteristics. The cap device described above requires threading of the cylinder and the cap. The casting device described above requires special threaded holes in the cylinder walls. The rods upon which the last described cylinder closure is mounted are expensive and add unnecessarily to the overall size of the cylinder. Many times the special machinery and special structure of these cylinder closing devices make the interchange of parts between cylinders very difficult and sometimes impossible.

In a double acting hydraulic cylinder, it is often desirable to change the relative positions of the ports in the two ends of the cylinder. The above described cylinder closures are not readily adapted to adjust the position of any port therein after the cylinder has been closed. In those cases where such an adjustment is possible, the closure must usually be removed from the cylinder and then remounted thereon.

Therefore, the principal object of my invention is to provide a cylinder closure means that can be easily removed from and installed on a cylinder unit.

A further object of my invention is to provide a cylinder closure means that will reduce the machining operations necessary for removability.

A still further object of my invention is to provide a cylinder closure means that can have its position within the cylinder rotatably adjusted.

. A still further object of my invention is to provide a cylinder closure means that is economical of manufacture, durable in use and refined in appearance. I

These and other objects will be apparent to those skilled in the art.

ice

My invention consists in the construction, arrangements, and combination, of the various parts of the de vice, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. l is a perspective view of a hydraulic cylinder utilizing my detachable closure means,

Fig. 2 is an enlarged scale vertical sectional view taken on the longitudinal axis of the cylinder of Fig. l. The cylinder and piston in this figure have been shown only in part to conserve space,

Fig. 3 is a perspective view of the end of a hydraulic cylinder upon which my device is being installed, and

Fig. 4 is a sectional view taken on line -44 of Fig. 2.

I have used the numeral 10 to generally designate a double-acting hydraulic cylinder. Cylinder 10 has a rigid closed end 12 and an open end designated by the numeral 14. A port 16 is located in the wall of cylinder 10 adjacent end 12 and is adapted to be connected to a source of hydraulic power.

A conventional piston 18 is slidably mounted within cylinder 10. Conventional O-rings 20 are mounted in grooves 22 of piston 18 to perform their usual sealing function. A piston rod 24 is detachably secured by one of its ends to piston 18 by nut assembly 26. The other end of piston rod 24 extends through the end 14 of cylinder 10 and detachably supports clevis member 28 in any convenient manner. The structure thus far described are those elements found in any conventional hydraulic cylinder.

As shown in Fig. 2, a groove 30 extends around the inside perimeter of cylinder 10 at a point near end 14 of the cylinder. A circular casting 32 having a diameter substantially equal to the inside diameter of cylinder It) is adapted to be rotatably and slidably inserted into the open end 14 of the cylinder. This casting 10 also has an opening 34 which enables it to slidably and rotatably embrace piston rod 24. This casting 32 can utilize any conventional means of preventing the seepage of hydraulic fluid past its inside or outside diameter. I have shown conventional 0 rings 36 and 38 which are mounted in grooves 40 and 42, respectively, on the inside and outside diameters of the casting. A grease ring 44 or similar structure can extend around the outside end of opening 34 to embrace piston rod 24.

A ring 46 with lugs 48, 50 and 52 can extend around the outside end of opening 34 and project slightly from the outside face 54 of casting 32. As shown in Fig. 2, ring 46 and lugs 48, 50 and 52 can be integrally formed with casting 32. A port 56 with passageway 58 can be formed within lug 48 and casting 32 if the cylinder is to be double-acting, but the presence of port 56 in this lug does not affect the primary function of the lug.

A groove 60 extends around the periphery of the outside surface 54 of casting 32. As the groove 60 passes through the lugs 48, 5'0 and 52, the groove is increased in size to form the groove portion 62 as shown in Fig. 2. Grooves 62 attain their increased size by extending into the respective lugs a distance substantially equal to the distance groove 60 extends into the face 54 of casting 32. This arrangement leaves the bottom of grooves 60 and 62 in the same plane. It should be noted that the efiective depth of grooves 62 as measured from left to right in Fig. 2 is slightly greater than the depth of groove 30 in cylinder 10.

A snap ring 64 is adapted to be placed within the grooves 60, 62 and 30 as hereafter will be seen. The ring 64 is generally of resilient, spring-like metallic construction and I have shown the ring to have two complete circular revolutions in its length. The number of revolutions in the ring 64 is not necessarily critical as long as the effective depths of grooves 36 and 62 are capable of enclosing the compressed depth of the ring. A diagonally bent portion 66 appears in the ring 64 at a point 360 from end 68. This portion 66 is utilized to prevent any uneven overlapping of the ring and to permit the ring to completely compress into a single plane defined essentially by grooves 60, 62 and 30. A cut-out portion 70 appears in end 68 of ring 64 to permit a tool to be used upon the ring as will be hereinafter described. The end of ring 64 opposite to end 68 (not shown) can be constructed similarly to end 68.

The normal installation of my closure device is as follows: The casting 32 is inserted into the open end 14 of cylinder It to a point where grooves 62 and 30 are in substantial alignment. The insertion of the casting 32 into the cylinder 16. is made possible by removing the clevis 28. from piston rod 24 and sliding the piston rod through the opening 34 in the casting,

After the grooves 62 in casting 32 have been substantially aligned with groove 30 in cylinder Ill, the end of ring 64 opposite to end 68 is threaded into one of the openings formed by the grooves 62 in any one of the lugs and the groove 30. The ring 64 is progressively fed into this opening and extends around the periphery of groove 36. The ring 64 meets with little resistance while its first 360 turn is being fed into groove 30. This is because the groove 30 (and the grooves 62) are deep enough to receive two full turns of the ring so the first turn of the ring receives little frictional resistance. It will be noted in Fig. 3 that the portion of ring 64 just entering the above described grooves passes. over lug 52 and then downward into and underneath lug 50. If the ring 64 ever binds in groove 30 because of the flex placed in it as it passes over one lug downward under the next adjacent lug, the binding may be overcome by rotating the casting 32 in the direction shown by the arrow in Fig. 3. Thus, instead of moving the ring with respect to tr e lug 50, the lug 50 is moved with respect to the ring and the same result of depositing the ring 64 in groove 30 is accomplished. In fact, this latter described method is mandatory when the second and last 360 turn of the ring is to be threaded into groove 30. For as the second turn of the ring begins to enter groove 39, the two thicknesses of the ring will begin to fill up groove 34) as shown in Fig. 2 and binding between the groove and the ring will result. Thereafter, no movement between the ring 64 and groove 30 can occur. But, as stated above, grooves 62 in the lugs 48, 50 and 52 are of slightly greater depth than groove 30 so it is possible for the casting 32 to. be rotated with respect to the stationary ring 64 which is then bound within groove 30. Obviously, the continued rotation of lug 50 on casting 32 will place the entire length of ring 64 in groove 30. As shown in Fig. 2, the complete insertion of both turns of the ring 64- in grooves 30 and 62 will prohibit the movement of the casting 32 along the longitudinal axis of the cylinder 10. Thus ring 64 can effectively lock the casting 32 within cylinder 10. It should be noted, however, that casting 32 can still be rotated within the. cylinder thus permitting the port 56 to be moved to any convenient. position about the periphery of the cylinder.

The practical aspects of the, operation ofv my device have somewhat dictated its specific structure. For example, it was. stated above that the grooves 62 in lugs 43,. 50 and 52 were slightly deeper than the groove 36 in cylinder 16. This arrangement was designed specifically to allow the lugs tov slide over the. ring while the ring was bound. in the narrow groove 30. But practice showed that if casting 32 had too many lugs with corresponding grooves 62,. the drag imposed upon the ring 64 by the combined surfaces of the grooves 62 in the rotating casting would overcome. the frictional bind irn-- posed upon the ring by groove and the ring would then turn with the casting. This, of course, would render the device. inoperative. I therefore discovered that only one lug was necessary to install the ring as described above. But it will be seen in Fig. 2 that if hydraulic pressure tries to force casting 32 out of cylinder 10, the portion of ring 64 in grooves and 62 will have a tendency to deflect and resist being sheared from the portion of the ring in groove 30. Therefore, to resist this deflection of the ring in a balanced manner, I utilized the three lugs 48, 50 and 52 on casting 32 and located them substantially at the third points around the periphery of the outside face 54 of the casting.

To remove the installed casting 32 from cylinder 10, I merely use any convenient tool on portion of ring 64 and pull the end 68 of the ring up and out of groove 36. While the end 68 is held in this position, the casting is rotated in a direction opposite to the direction to which it was turned during the installing operation, and the nearest lug adjacent the end 68 is permitted to go under and support the raised end. Obviously, the continued rotation of the lug and casting in the manner described will result in the subsequent removal of ring 64 from groove 30. The casting 32 may then be slidably removed from the cylinder 10 and piston rod 24. Essentially, the removal of the casting from the cylinder is the reverse of the installation process.

Thus, it will be seen that my device accomplishes at least its stated objectives.

Some changes may be made in the construction and arrangement of my closure means for cylinder units without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivaa lents which may be reasonably included within their SCO-P.

I claim:

1:. In a device of the class described, a hollow cylinder having an open. end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted with in said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, and means on said casting whereby the engagement of said means with one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from theopening formed by said grooves; the grooves in said casting and said cylinder maintaining at all times constant radius in the portion of said ring member mounted therein.

2. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted within said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, and a lug on said casting whereby the engagement of said lugwith one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from the opening formed by said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

3. In a device of the class described, a hollow cylinder having an open end,a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted with,- in said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, the depth of the groove in said casting being slightly greater than the corresponding depth of the groove in said' cylinder, and means on. said casting whereby the. engagement of said means with one of said free ends of said ring member and the inducement of rotational movementbetween said casting and said cylinder will remove said ring member from the opening formed by said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

4. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted within said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, the depth of the groove in said casting being slightly greater than the corresponding depth of the groove in said cylinder, and a lug on said casting whereby the engagement of said lug with one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from the opening formed by said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said .ring member mounted therein.

5. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted within said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, at least a portion of the groove in said casting communicating with the exterior face of said casting; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

6. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted within said cylinder, a non-continuous ring member mounted in the groove in said cylinder and having a portion of its width extending therefrom, at least one lug on the outside face of said casting, and a groove in said lug embracing the portion of said ring member extending from the groove in said cylinder; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

7. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted within said cylinder, a non-continuous ring member mounted in the groove in said cylinder and having a portion of its width extending therefrom, at least one lug on the outside face of said casting, and a groove in said lug embracing the portion of said ring member extending from the groove in said cylinder, the depth of the groove in said lug being greater than the corresponding depth of the groove in said cylinder and the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

8. In a device of the class described, a hollow cylinder having an open end, a groove on the inside of said cylinder adjacent said open end, a casting rotatably mounted said cylinder, a groove in said casting registering with the groove in said cylinder, a flat ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, and means on said casting whereby the engagement of said means with one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from the opening formed by said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

9. In a device of the class described, a cylinder, a groove on said cylinder, a casting rotatably mounted on said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, and means on said casting whereby the engagement of said means with one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from the opening formed by the registering of said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

10. In a device of the class described, a cylinder, a groove on said cylinder, a casting rotatably mounted on said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, the depth of the grooves in said casting being slightly greater than the corresponding depth of the groove in said cylinder, and means on said casting whereby the engagement of said means with one of said free ends of said ring member and the inducement of rotational movement between said casting and said cylinder will remove said ring member from the opening formed by the registering of said grooves; the grooves in said casting and said cylinder maintaining at all times a constant radius in the portion of said ring member mounted therein.

11. In a device of the class described, a cylinder, a groove on said cylinder, a casting rotatably mounted on said cylinder, a groove in said casting registering with the groove in said cylinder, a ring member having free ends and mounted in the opening formed by the registering of the grooves in said cylinder and said casting, at least a portion of the groove in said casting communicating with the exterior face of said casting; the grooves in said casting and said cylinder maintaining at all timesa constant radius in the portion of said ring member mounted therein.

References Cited in the file of this patent UNITED STATES PATENTS 

